Surveying is used for identifying subterranean elements, such as hydrocarbon reservoirs, freshwater aquifers, gas injection reservoirs, and so forth. Surveying can include seismic surveying or electromagnetic (EM) surveying. In seismic surveying, seismic sources are placed in various locations above an earth surface or sea floor, with the seismic sources activated to generate seismic waves directed into the subterranean structure.
The seismic waves generated by a seismic source travel into the subterranean structure, with a portion of the seismic waves reflected back to the surface for receipt by seismic receivers (e.g., geophones, hydrophones, etc.). These seismic receivers produce signals that represent detected seismic waves. Signals from seismic receivers are processed to yield information about the content and characteristic of the subterranean structure.
EM surveying involves deployment of one or more EM sources that produce EM waves that are propagated into the subterranean structure. EM signals are affected by elements in the subterranean structure, and the affected signals are detected by EM receivers, which are then processed to yield information about the content and characteristic of the subterranean structure.
A survey system can include a number of different types of units, such as different types of concentrator units (which are basically routing or switch units to enable routing and switching of messages in the survey system). The logistics involved in physically laying out the different types of units and connecting them together, particularly in a large survey system that may have hundreds or thousands of units, can lead to increased cost associated with deployment of the survey system. Typically, once an entire survey system is laid out, the survey system is powered up and connected to a central recording system, such as a recording truck. The central recording system can then be used to test the entire system, which can be a relatively complex task. If failures are detected, the survey system attempts to generate diagnostics to identify the causes of the various failures and the units that are faulty. Maintenance crews can then be sent to remote locations to fix the identified problems. Example problems include faulty units, faulty cables, faulty connectors, and so forth.
Because of the inherent point-to-point connections between units of a survey system, multiple failures may often not be discovered together (because it is difficult to isolate the source of failure due to error accumulation), and several rounds of testing may have to be performed (with corresponding repairs) prior to successful setup of the survey system. Wasting time doing the several rounds of testing may be very costly for survey operations.
In survey systems deployed in remote or difficult to access environments, such as in the Arctic or other remote locations, repairing or replacing faulty components can be tedious, time consuming, and sometimes impossible. Also, it may be difficult to take cables apart to tab into the system for repair or replacement tasks. As a result, conventional techniques of deploying a survey system can be associated with relatively high costs and reduced reliability.